Mixer having a device for cooling of material to be mixed

ABSTRACT

A mixer having a device for the cooling of powdered, granular, liquid or otherwise flowable material to be mixed, in particular plastics agglomerates or the like, consisting of a cup-shaped mixture container which may be double-walled and through which a coolant flows, and which has a mixing implement rotating in its center over the bottom thereof.

United States Patent 1191 Bittner et a1.

[451 June 28, 1974 MIXER HAVING A DEVICE FOR COOLING OF MATERIAL TO BE MIXED Inventors: Wolfgang Bittner, Dusseldorf;

Karl-August Berker; Gunter Claes, both of Detmold, all of Germany Gunther Papenmier KG Maschinen-und Apparatebau, Detmold, Germany Filed: Sept. 6, 1972 Appl. No.: 286,542

[73] Assignee:

[30] Foreign Application Priority Data Sept. 15. 1971 Germany..." 2146150 US. Cl 165/109, 259/66, 259/107, 1 259/1310. 18

Int. Cl .L.. F281 13/12 [58] Field of Search 165/ 109; 74/665 GA; 259/66, 107, DIG. 18

References Cited UNITED STATES PATENTS 5/1922, Barton 74/665 GA f 2,085,924 7/1937 Rieglcr 165/109 X 2,557,622 6/1951 Trier 165/109 X 2,645,461 7/1953 Brown et a1. 165/109 X 3,387,651 6/1968 Berker 165/109 3,400,051 9/1968 Hofschneidcr 165/109 X 3,546,430 12/1970 Kane 165/109 X 3,554,274 1/1971 Herfeld 165/109 X FOREIGN PATENTS OR APPLlCATlONS 244,267 1910 Germany 165/109 Primary ExaminerA1bert W. Davis, Jr. Assistant Examiner-S. J. Richter A mixer having a device for the cooling of powdered, granular, liquid or otherwise flowable material to be mixed, in particular plastics agglomerates or the like, consisting of a cup-shaped mixture container which may be double-walled and through which a coolant flows, and which has a mixing implement rotating in its center over the bottom thereof.

ABSTRACT 19 Claims, 3 Drawing Figures PATENTEDJUR 28 I914 sum 1 [1F 2 1' MIXER HAVING A DEVICE FOR COOLING OF MATERIAL TO BE MIXED BACKGROUND OF THE INVENTION particular as a bucket wheel, extending in the radial direction to a location beyond the cooling annulus preferably to a location a short distance upstream of the container inner wall. It is true that, in this way, there is achieved on the material being circulated a travel path of the mixing material to be cooledwhich is such that the latter is displaced through the annular chamber between the outer surface of the annulus and the inner surface of the container and also along the inner surface of the annulus, so that the cooling time is considerably reducedrelative to that achieved in a mixer of hitherto-conventional design. However, this is true only if specific conditions are observed.

It has been found that materials to be mixed behave in very different ways depending on their composition, nature and type, in particular in a cooling mixer of the prior-known and above-described type. The difference in behavior consists above all in that the flow pattern of the. material to be mixed varies on mixing for the purposes of cooling, so that the cooled'surfaces over which the material to be mixed passes are of varying size,the result of this being a longer or shorter treatment time for the material to be mixed in order to cool the latter down to apredetermined, desired temperature. t I

- The invention is based on the problem of how to provide a cooling mixer which is able to bring the material to be mixed, in theshortest possible time, to a desirbed temperature and, in particular, to achieve the result that the treatment time during cooling always corresponds with maximum exactitude to the time required for thepreparation of the material to be mixed in a high-speed mixer, being at least not substantially longer. Such disadvantages have'frequently been encountered in particular in mixer combinations consisting of a processing high-speed mixer and a sequentially connected cooling mixer, so that the efficiency of the high-speed mixer cannot be fully utilized because the efficiency of the: cooling mixer was lower, unless the cooling mixer was designed to be disproportionately larger and more efficientso as to achieve the same treatment times as in the high-speed mixer. This requires, however, a considerable additional expenditure.

SUMMARY OF THE INVENTION As a solution to the aforementioned problem, according to the present invention, a cooling mixer of the type under consideration is proposed and includes novel cooling elements which project into the inner space of the mixing container. The cooling elements are double-walled, spade"-shaped elements, through which coolant flows, and which are designed as baffle plates. Such cooling elements are preferably concavely curved with reference to the central axis of the mixing container, and are arranged one after the other in spaced relationship relative to the inner wall of the mixing container and in spaced relationship relative to each other in the peripheral direction, and being adapted to be so adjusted relative to the incident flow of mixing material that the run-off edge is-located radially further inwardly than the incident-flow edge. Due to such design of the cooling elements projecting into the internal space or chamber of the mixing container, the cooling elements may be adjusted into an optimum position, in adaptation to the material to be mixed in each particular instance and retained in this position, so that the material to be mixed passes, during operation, in every case over the largest possible cooled surface of the cooling elements.

Advantageously, the cooling elements are disposed on a holding shaft or the like through which the coolant is fed to or discharged from the cooling elements. The holding shafts of the cooling elements may be mounted in the upper zone of the mixing container'and/or at any optional location on the walls of the mixing container. Preferrable mounting locations are in the upper zone of the walls of the mixingcontainer or in the lateral wall.-

A further improvement in the cooling efficiency can be achieved by designing the bottom of the mixing container to be double-walled and introducing into it a coolantrouted in the desired manner by baffle plates arranged preferably spirally in the double bottom.

Further novel features and other'objects of this invention will become apparent from the following detailed description, discussion and the appended claims taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS Preferred structural embodiments of this invention are disclosed in the accompanying drawings, in which:

FIG. 1 is a partial, radial section through one half of a mixing container of a mixer;

FIG. 2, drawn on a smaller scale, is a horizontal section taken on line IIII of FIG. 1, and diagrammatically illustrates the disposition of the coolant elements; and

. FIG. 3 is an enlarged scale, detail section through the mixing container walls of a second embodiment at the zone of a modified retaining means for a cooling element.

As can be seen from the drawings, a mixing container is provided with double walls 11 and a double bottom 12 and has a mixing implement 13 for circulating the material to be mixed in the mixing container. Arranged in inwardly spaced relationship relative to the inner wall of the mixing container are double-wall cooling elements 14 of spade shape, or some similar shape, and which are arranged disposed one behind the other with predetermined spacing relative to each other in the peripheral direction. Cooling elements 14 preferably have a concave curvature relative to the central axis 15 of the mixing container (FIG. 2), and are carried by a shaft 16 mounted for pivoting in bearings 17 in the upper zone 18 or top wall of the mixing container.

It is possible, using conventional means, to lock the shaft 16 of the cooling elements 14in their bearings 17 after they are adjusted to a desired position. Advantageously, each shaft 16 has, externally of the mixing container, a pinion 19 secured thereto and meshing with a toothed rim 20 rotatably mounted on the mixing container. Thus, by rotating the toothed rim 20, all of the pinions 19 of the cooling elements shafts 16 can be simultaneously adjusted through the same angular value. The shaft 16 of each cooling element is, how ever, also vertically adjustable, for example by means of a threaded ring 21 screwed on to the cooling elements and bearing on the pinion l9. Shaft 16 is hollow and disposed in it is a coolant feed pipe 22 routing the coolant into the lower zone of the cooling element 14. Arranged in the cavity in the cooling element 14 are, advantageously, baffle plates 23 which may if so desired be perforated for more satisfactorily distributing the coolant as it flows through the inner space of the cooling element. Arranged at the upper end of the shaft 16 is a head member 24 for connection to the coolant feed and discharge hoses 25 or 26.

The double-walled bottom 12 also should preferrably contain baffle plates 27 extending outwardly from a central partition ring 28. The coolant feed stub 29 debouches into the annular chamber 30 within the coolant guide ring 28 and formed in that ring are apertures 31 enabling outflow of the coolant.

The rotating mixing implement 13 adjacent the container bottom wall circulates the material being mixed within the mixing container, centrifugally hurling it outwardly. The material flows along the cooled inner wall and ascends at the lateral wall up to a predetermined level, whereupon it undergoes a radial inflow and flows back in the center of the container again passing to the mixing implement. The cooling elements 14 are so adjusted into the flow path of the mixing material, i.e., they are so adjusted with respect to their height and angular position that the cooled inner and outer faces of the cooling elements 14 have an optimum flow of mixing material to be cooled passing over them.

In a mixer made according to the embodiment illustrated in FIG. 3, the cooling elements 14 are carried by a holding tube or shaft 41 arranged with a ball joint bearing 42 in the double-walled lateral wall 11 of the mixing container. A tensioning ring on the ball 44 and with the ball cup 43 retains the ball in the adjusted position. Thereby, it is possible to dispose and retain the cooling elements 14' in a desired position. The holding tube 41 may be adjusted in all directions within a predetermined range. Furthermore, it is advantageous to arrange between the cooling elements 14' and the holding tube 41 ajoint 46 affording further possibilities for adjustment. In order to be able to vary the spacing of the cooling element 14 relative to the inner wall of the mixing container, there may be arranged on the holding tube 41 between the cooling element 14 or the joint 46 and the ball 44 of the joint 46 spacer sleeves or rings locked together by a threaded ring 47 on the outer end of the holding tube 41. Disposed on the outer end of the holding tube 41 is a head member 48 to which are connected the flexible tubes 49 or 50 for the infeed or discharge of the coolant. The coolant is supplied to the cooling elements 14' through the holding tube.

Tests have shown that it is possible to achieve with a cooling mixer of the type according to the invention cooling times which correspond to the processing times for plastics in a high-speed mixer, without it being necessary (as had hitherto been necessary) to design the cooling mixer to be larger, to an extreme degree, than the high-speed mixer.

The mixer having the device according to the invention is not restricted to the embodiments described purely by way of example. On the contrary, it is possible to provide in the holding means for the cooling elements for a wide range of variants, without thereby departing from the basic idea underlying the invention. Thus, for many applications, the cooling elements may be carried by a holding tube or shaft without a ball joint bearing, i.e., arranged rigidly in the double-walled lateral wall of the mixing container or under the cover or lid of the mixing container. It is also possible (with further advantage in respect of costs and with reference to the range of application) to employ the cooling mixer designed in accordance with the invention as a heating mixer for the processing of granular, gellike or similar plastics or the like.

The invention may be embodied in other specific forms without departing from the scope, spirit, or essential characteristics thereof. Present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope and spirit of the invention being indicated by the appended claims rather than by the foregoing description and all changes which come within the meaning and range of equivalency of the claims are, therefore, intended to be embraced therein.

What is claimed and desired to be secured by Letter Patent is:

1. A mixer including means for the cooling of powdered, granular, liquid or otherwise flowable material to be mixed, in particular plastics agglomerates or the like, comprising: a double walled cup-shaped mixing container through which coolant flows; said mixing container having a mixing implement rotating in the center over its bottom; and a plurality of double-walled cooling elements through which coolant flows and which are concavely curved relative to the middle axis of the container mounted in the inner container space in spaced relationship relative to the container inner wall; said plurality of cooling elements having spade"- shape and arranged in spaced relationship in the peripheral direction and including adjustable means enabling variations in disposition of the run-off edge located radially further inwardly than the incident-flow edge.

2. A mixer including means for varying the temperature of material to be mixed comprising: a cup-shaped mixing container comprising confining double bottom and double side walls through which coolant flows; a mixing implement; means mounting the mixing implement within the container for rotation about the vertical axis of the container and disposed adjacent the container bottom wall; a plurality of arcuate, spade shaped hollow heat exchange elements each element with a concave radially inwardly facing surface and with leading and trailing edges disposed in circumferentially spaced relationship in an annular zone around the axis of the container, and spaced inwardly from the container side wall, each element having means enabling circulatin of a heat exchange medium therethrough from exterior of the container; and means mounting said elements for selective adjustment so the edges can be variably located at different dispositions with the trailing edges disposed closer to the container axis than are the leading edges.

3. A mixer as defined in claim 2, wherein the means mounting said cooling elements are pivotal mounting means foreach element.

4. A mixer as defined in claim 3, wherein said means mounting said elements include a shaft for each mounted in a side wall of said container.

5. A mixer as defined in claim 4, wherein each said pivotal mounting means journals its associated shaft for rotation about a fixed axis.

6. A mixer as defined in claim 4, wherein said elements are mounted for pivoting about an axis offset from a vertical axis.

7. A mixer as defined in claim 4, wherein said pivotal mounting means is a ball and sockect bearing joint.

8. A mixer as defined in claim 7, wherein said joint has means enabling adjustable axially positioning of the shaft and rotary adjustment of the shaft and associated element.

9. A mixer as defined in claim 7, wherein said mounting shafts provide the flow passages for the heat exchange medium to communicate to the interior of said associated elements.

10. A mixer as defined in claim 3, wherein each element includes internal flow directing baffles.

11. A mixer as defined in claim 4, wherein each element is adjustable about a vertical axis.

12. A mixer as defined in claim 11, wherein said elements are adjustable as to vertical position along the axis of the shafts.

13. A mixer as defined in claim 12, wherein the elements are arranged so that the radial spacing from the inner wall surface of the mixing container is adjustable.

14. A mixer according to claim 2, wherein said adjustable element mounting means enable the elements to be pivoted and adjusted about a vertical axis.

15. A mixer according to claim 14, wherein said adjustable mounting means enable the elements to be adjustable as to vertical position.

16. A mixer according to claim 14, wherein the incident-flow edge of the elements are shaped to a contour complementing the profile of the inner wall surface of adjustment.

UNITED STATES PATENT OT'FFICE' CERTIFICATE OF CORRECTION Patent No. 3 ;820 597 I Dat d June 28 1974 Inventm-(s) Wlfgang Bittner et a1 It is certified that'error appears in the above-identified patent and that said' Letters Patent are hereby corrected as shown below:

Column 1, line 43, change "de sirbed" to v -desired---. I I I Colmnn 3, line #9, change "the" (third I occurrence) to --an. I

Columnfi, line 22 change "gellike" to -gel-like--. Collinin l, last line (Claim 2) change "circulatin" to -circulati on--.

Signed. and Sealed this 29th day of October 19 74.

Attest:

McCOY M. GIBSON JR. C. MARSHALL DANN Attesting Officer Commissioner of Patents FORM po-mso (10-69) USCOMM-DC 003764 69 

1. A mixer including means for the cooling of powdered, granular, liquid or otherwise flowable material to be mixed, in particular plastics agglomerates or the like, comprising: a double walled cup-shaped mixing container through which coolant flows; said mixing container having a mixing implement rotating in the center over its bottom; and a plurality of double-walled cooling elements through which coolant flows and which are concavely curved relative to the middle axis of the container mounted in the inner container space in spaced relationship relative to the container inner wall; said plurality of cooling elements having ''''spade''''-shape and arranged in spaced relationship in the peripheral direction and including adjustable means enabling variations in disposition of the run-off edge located radially further inwardly than the incident-flow edge.
 2. A mixer including means for varying the temperature of material to be mixed comprising: a cup-shaped mixing container comprising confining double bottom and double side walls through which coolant flows; a mixing implement; means mounting the mixing implement within the container for rotation about the vertical axis of the container and disposed adjacent the container bottom wall; a plurality of arcuate, spade shaped hollow heat exchange elements each element with a concave radially inwardly facing surface and with leading and trailing edges disposed in circumferentially spaced relationship in an annular zone around the axis of the container, and spaced inwardly from the container side wall, each element having means enabling circulatin of a heat exchange medium therethrough from exterior of the container; and means mounting said elements for selective adjustment so the edges can be variably located at different dispositions with the trailing edges disposed closer to the container axis than are the leading edges.
 3. A mixer as defined in claim 2, wherein the means mounting said cooling elements are pivotal mounting means for each element.
 4. A mixer as defined in claim 3, wherein said means mounting said elements include a shaft for each mounted in a side wall of said container.
 5. A mixer as defined in claim 4, wherein each said pivotal mounting means journals its associated shaft for rotation about a fixed axis.
 6. A mixer as defined in claim 4, wherein said elements are mounted for pivoting about an axis offset from a vertical axis.
 7. A mixer as defined in claim 4, wherein said pivotal mounting means is a ball and sockect bearing joint.
 8. A mixer as defined in claim 7, wherein said joint has means enabling adjustable axially positioning of the shaft and rotary adjustment of the shaft and associated element.
 9. A mixer as defined in claim 7, wherein said mounting shafts provide the flow passages for the heat exchange medium to communicate to the interior of said associated elements.
 10. A mixer as defined in claim 3, wherein each element includes internal flow directing baffles.
 11. A mixer as defined in claim 4, wherein each element is adJustable about a vertical axis.
 12. A mixer as defined in claim 11, wherein said elements are adjustable as to vertical position along the axis of the shafts.
 13. A mixer as defined in claim 12, wherein the elements are arranged so that the radial spacing from the inner wall surface of the mixing container is adjustable.
 14. A mixer according to claim 2, wherein said adjustable element mounting means enable the elements to be pivoted and adjusted about a vertical axis.
 15. A mixer according to claim 14, wherein said adjustable mounting means enable the elements to be adjustable as to vertical position.
 16. A mixer according to claim 14, wherein the incident-flow edge of the elements are shaped to a contour complementing the profile of the inner wall surface of the mixing container.
 17. A mixer according to claim 14, wherein the elements have a sharp-edged incident-flow edge.
 18. A mixer according to claim 14, wherein each adjustable element mounting means includes a shaft journalled in an upper mixing container wall.
 19. A mixer according to claim 18, characterized in that a pinion is secured to each of the shafts of the vane elements and an adjusting ring gear is mounted for rotation on the mixing container and meshes with all of said pinions to enable simultaneous cooling element adjustment. 